Now that you have a new Ecobee Thermostat, you’ll want to take advantage of all of its features, including those that come with its compatible sensors. Of course, if you’ve never owned sensors, you’re probably curious about how they function or if the expense justifies their capabilities. This FAQ was put together to answer all of the questions you may have regarding Ecobee sensors and how they work with Ecobee Thermostats.

What Does an Ecobee Sensor Do?

Smart thermostats are great investments, giving you a broader range of control while saving money on unnecessary cooling and heating costs. However, a thermostat—regardless of whether it is smart or standard—only measures the room’s temperature where the thermostat is installed.

Ecobee SmartSensors assist the Ecobee Thermostat by measuring the other rooms’ temperature and relaying that information back. They’re small, discreet, and effective—considering that the Ecobee Thermostat can’t measure temperatures outside of its immediate vicinity.

If your home is well-insulated and the temperature throughout doesn’t fluctuate, purchasing an Ecobee SmartSensor probably isn’t a necessary expenditure. They’re great for rooms with less insulation or rooms that spend more time in the sun, especially during the summer.

Pros and Cons of Ecobee Sensors

For the most part, it’s hard to buy Ecobee Sensors as a single device, and they don’t detect everything that the thermostat does. Ecobee SmartSensors don’t detect humidity and gather less data than the Ecobee Thermostat. However, they’re always available on Amazon and at major electronics retailers.

Ecobee SmartSensors are generally sold in packs. If you need more than one, that’s great. However, if you need a single sensor for a troublesome room, you’ll find that buying a single sensor is difficult. Two-pack varieties—such as this one—are sold on Amazon. You are far more likely to find a single sensor on eBay; however, they’ll likely be used.

If humidity is a concern where you live, the Ecobee sensors won’t be of much use to you in that regard. They’re also sensitive to other elements; when setting them up, be careful not to place them around any objects that give off heat or cold.

How Do Ecobee Room Sensors Work?

Ecobee room sensors work by detecting the room temperature in the area in which the user installs it. The Ecobee SmartSensors relay information from other rooms in the house, then the thermostat adjusts the average temperature in your home to try and control hot and cold spots.

Ecobee SmartSensors also have a feature called “Follow Me,” which allows the sensor to detect what room you are in and adjust the temperature to your preferred setting. If you have multiple SmartSensors throughout the home, the temperature will adjust as you move from room to room.

How Many Ecobee SmartSensors Do I Need?

Most users will need a minimum of two Ecobee sensors with their Ecobee thermostat. However, it boils down to what you prefer and if you have cold and hot spots throughout the home that your Ecobee Thermostat can’t control.

Ideally, you’ll want a SmartSensor for any room in which there’s a marked temperature difference, especially during the extremes of winter and summer.

How Long Do Ecobee SmartSensors Stay Occupied?

Ecobee SmartSensors stay occupied for up to 2 hours in Smart Home and Smart Away modes. They become occupied when motion is detected—after which they follow the directive of whichever mode they are set on.

There are three modes in which an Ecobee SmartSensor switches to occupied:

  • Home
  • Away
  • Follow Me

When Follow Me mode is active, the SmartSensor will enter occupied status for thirty minutes if no further motion is detected.

Where Should I Place My Ecobee Sensors?

Ecobee sensors should be placed in rooms where the ambient temperature is furthest away from the temperature you prefer, or the reading on the Ecobee Thermostat.

Keep in mind, SmartSensors have a range of approximately 60 feet. This is an approximate measure because walls, materials such as steel, concrete, and brick, and other devices that communicate through Wi-Fi may decrease the overall range of the SmartSensor.

Also, Ecobee sensors should be placed in areas away from direct sunlight or other sources of heat or cold. Space heaters or direct sunlight will throw off the ambient temperature readings of the device.

What’s the Difference Between Ecobee SmartSensor and Room Sensor?

The main difference between the Ecobee SmartSensor and the Room Sensor is that the SmartSensor is the upgraded, next-gen version that does everything better than its predecessor, including:

  • More battery life
  • Larger viewing angle
  • Greater range
  • Pet immunity
  • Easier pairing

However, despite these improvements, the SmartSensor and the Ecobee Room Sensor do the same things. The only new feature with the SmartSensor is pet immunity, which identifies if a pet is in the room and avoids going into occupancy mode to activate the thermostat.

As far as upgrades go, the SmartSensor has improved battery life from one year to five years and pairs via the Alexa app—rather than users having to stand next to the thermostat with the Room Sensor. Also, the viewing angle is increased by 20 degrees over the Room Sensor, and the SmartSensor has a sleeker design with more rounded corners.

How Do I Attach an Ecobee Sensor to the Wall?

To attach an Ecobee sensor to the wall, first ensure its base plate and the wall are clean. Peel off the protective layer of the adhesive that came with the sensor and place the sticky side on the sensor’s base. Then, peel off the remaining layer and firmly press the base against the wall.

It’s that simple, except to some, adhesive isn’t the desired application. As an alternate method, you can also purchase wall mounts designed for the SmartSensors. There are also available 3D printed mounts, as well as shadow shelves. If you use the stand to place the sensor on a shelf, the stand plate replaces the backplate of the SmartSensor.

The SmartSensor may come with adhesive, but the small mount is also designed for a screw. If you’re mounting it on sheetrock, be sure to use an anchor to expand into the sheetrock for a more reliable mount.

Where Can I Buy an Ecobee SmartSensor Battery?

Online, you can purchase an Ecobee SmartSensor battery through Amazon, and they’re relatively inexpensive and long-lasting. They’re also available at just about any local retailer, such as Walmart, Target, BestBuy, and others.

The battery used in the Ecobee SmartSensor is a 3-volt, CR-2477 Lithium Manganese Dioxide and can be found just about anywhere. There are several variations for this type of battery, and looks alone can be confusing; just be sure you see the CR-2477 number on the packaging.

How Do I Find a Lost Ecobee SmartSensor?

There is no way for users to track down a lost Ecobee SmartSensor because the devices are not equipped with location alarms; however, you do have the option to scroll down on your Ecobee Thermostat’s main menu to the sensor to see if it is still active.

As for physically locating an Ecobee SmartSensor, it’s up to you to look under the bed. As mentioned above, Ecobee SmartSensors don’t come equipped with location alarms. The best you can do is find that it is still active on the thermostat’s network.

If it is active, occupancy may activate when you walk into a room, so checking the Ecobee Thermostat to see the status of its sensors can be helpful, as your movement could at least narrow its location down. As far as locating a SmartSensor that is out of battery, well, there are always bloodhounds!

Why Does My Ecobee SmartSensor Say Unavailable?

Like any Wi-Fi device, there are a few reasons that communication between the SmartSensor and thermostat could be disrupted and become “unavailable”:

  • SmartSensor’s battery is low
  • Interference
  • Distance from the thermostat

If the battery in your SmartSensor is low, you’ll either receive a notification through the app or the Ecobee Thermostat. To replace the battery, simply remove the backplate on the sensor, remove the old battery, and replace it with the new battery with the positive side facing towards you.

If interference is the culprit, you won’t immediately know where the problem comes from. You’ll have to check devices throughout the house, especially recently added devices such as baby monitors, walkie-talkies, or home phones. If those devices or any new smart additions to your home are near the SmartSensor, try rearranging them to restore the signal to the sensor.

Ecobee Room Sensors can operate up to 45 feet from the Ecobee Thermostat. SmartSensors have an extended range of 60 feet. When installing a SmartSensor, it’s important to find a happy medium, as walls, concrete, brick, and some metals could impair signal distance.

What If My Ecobee SmartSensor Won’t Pair?

If your Ecobee SmartSensor won’t pair, the first thing you want to do is ensure that the sensor isn’t beyond the 60-foot range limit for the SmartSensor, or the 45-foot range limit for the Room Sensor. If neither of these cases is an issue, try resetting the sensor.

There is no reset button to return the sensor to pairing mode. What you’ll have to do is remove the backplate and then the battery. Wait for at least two minutes, then replace the battery, and the device will attempt to pair again.

If it doesn’t pair again, repeat the process but stand closer to the Wi-Fi router or thermostat—depending on your device—until it pairs, then progressively move outward from the router or thermostat.

What If I Want to Unpair My SmartSensor?

If you want to unpair your sensor, you’ll have to do so from the Ecobee Thermostat by accessing the Sensors menu.

On the main menu, select the three horizontal lines (hamburger menu) at the screen’s bottom-left corner. Then:

  1. Select Sensors on the following menu. The next screen will list the sensors you currently have connected to your thermostat’s network.
  2. Select the sensor you would like to unpair, then select the trash symbol in the upper right corner of the screen. You’ll be given the option to unpair the sensor.

How Does the Ecobee Thermostat Assign Weight to SmartSensors in Follow Me Mode?

The thermostat will assign more weight to the SmartSensor in the room you spend the most time in; the sensors in the most used room will weigh heavier than the sensors in rooms activated by simply passing through.

It’s easy to see how the simple act of passing through a room will switch a SmartSensor to occupancy and throw off the average temperature settings in the home. Just walking through the den to get to the living room doesn’t mean you want the den to be the deciding factor in the Ecobee Thermostat’s temperature calculations.

What Is the Best SmartSensor Placement for the Pet Immunity Feature?

In most cases, the best SmartSensor placement for the pet immunity feature is 6 ½ feet above the floor. However, keep in mind that the optimal height placement for ambient temperature readings is four feet.

If the sensor is set too low, and you’re getting false occupancy when your pet is in the room, try moving it up a little higher. It’s not likely to affect the temperature reading too much if the SmartSensor is placed in an optimal area, away from sunlight or any other devices that give off heat.

What Are the Maximum Number of Sensors the Ecobee Thermostat Can Accommodate?

The Ecobee Thermostat can accommodate up to 32 sensors, which is more than enough even for a home with multiple stories.

Also, SmartSensors and SmartSensors for doors and windows will all pair with the Ecobee 3, Ecobee 3 Lite, and the Ecobee 4. Thirty-two sensors will cover every room, window, and door in even the largest of homes.